15. To find the quotient, decompose the dividend into obvious
15. multiples of the divisor.

a)

96 3

=

90 3

+

63

=

32

b)

63 3

=

60 3

+

33

=

21

c)

128 4

=

120 4

+

84

=

32

d)

186 6

=

180 6

+

66

=

31

e)

265 5

=

250 5

+

15 5

=

53

16. Decompose the dividend into multiples of the divisor. Find the16. quotient.

a)

78 3

=

60 3

+

18 3

=

26

b)

92 4

=

80 4

+

12 4

=

23

c)

85 5

=

50 5

+

35 5

=

17

d)

91 7

=

70 7

+

21 7

=

13

e)

96 8

=

80 8

+

16 8

=

12

f)

56 4

=

40 4

+

16 4

=

14

g)

45 3

=

30 3

+

15 3

=

15

h)

84 6

=

60 6

+

24 6

=

14

17. Decompose each dividend into multiples of the divisor, and find the17. quotient. (Try the divisor into the first two digits of the dividend.) 24. Check your answer: Multiply the quotient times the divisor.

a)

237 3

=

210 3

+

27 3

=

79

b)

184 4

=

160 4

+

24 4

=

46

c)

185 5

=

150 5

+

35 5

=

37

d)

378 6

=

360 6

+

18 6

=

63

e)

441 7

=

63

f)

456 8

=

57

g)

105 7

=

15

h)

512 8

=

64

i)

432 9

=

450 9

−

18 9

=

48

j)

267 3

=

270 3

−

33

=

89

k)

136 4

=

34

l)

396 9

=

44

m)

385 5

=

77

n)

276 6

=

46

18. Inexact division. Write each quotient as a mixed number.

a)

75

=

1

25

b)

26 3

=

8

23

c)

23 9

=

2

59

d)

31 8

=

3

78

e)

46 7

=

6

47

f)

39 4

=

9

34

g)

6512

=

5

512

h)

53 6

=

8

56

Can you do these mentally? Decompose the dividend.

19. How many 7's are there in 644? 92.644 = 630 + 14.

20. What number times 9 is 351? 39.351 = 360 − 9.

21. How many 8-inch boards could you cut from a piece that is 120 27. inches? 15.120 = 80 + 40.

22. In 5 hours, Arlene was able to drive 315 miles. How far did she 30. travel in 1 hour? That is, what was her speed? Miles per hours.27. 63 mph.315 = 300 + 15.

23. Helen took 6 exams, and the total of all her grades was 510. What 32. was her average grade? 85.510 = 480 + 30.

24. Joe borrowed $408, and agreed to pay it back in one year in equal 32. monthly payments. How much will he pay each month?32. $34.408 = 360 + 48. Divide each by 12.

25. 4 jackets that cost the same, together cost $304. How much did each27. one cost? $76.304 = 280 + 24.

26. You have $425 from which you plan to make payments of $35 each. 26. How many payments will you be able to make? 12.27. 425 = 350 + 70 + 5 = 12 × 35 + 5.

27. A club wants to raise $1400. If it sells tickets at $5 each, how many 27. tickets must it sell? 280.1400 = 1000 + 400.

28. Divide $882 equally among 9 people. $98 each.882 = 900 − 18.

The problems following the next Lesson will include calculator problems.